Typically, utility company water is provided to users via an underground pipe causing geothermal energy transfer. As water enter into a (GEWH) Gas or Electric Water Heater, in a home or business, the GEWH must increase the water temperature for house or building use. Geothermal energy affects water temperature and causes water to have a temperature, which is based both on earth temperature and water pipe temperature. For example, a 100° F. day may yield water at 70° F. for delivery to the inlet of a GEWH.
Several solar devices for using solar energy to heat water exist to increase water temperature prior to entering GEWH. As a solution various solar heat transfer devices have been placed in or around attics, rooftops and heat sources using various configurations to transfer heat from the solar device to water. These devices can run out of hot water at night or on a cooler day, these devices supply cooler water to the GEWH than utility company water, thus causing the GEWH to consume more energy to heat the cooler water.
One common problem with solar water heating devices is, at times, they provide water into a GEWH at temperatures below the normal utility water feed temperature thereby causing cooler water to enter the GEWH, thus causing more energy use. For instance on a day when the temperature high reaches 80° F., a solar collector may reach over 140° F. and the solar collector works fine. But, by early morning, the ambient temperature may be 55° F. and the solar collector has now become a cooling system. For instance as morning showers are taken, a solar heat transfer device can remove heat from the utility water feed causing cooler water to be distributed into the GEWH (colder than the utility water feed temperature).
A solar water heating system may provide water at 120° F. into a GEWH; this 120° F. water is typically cooler than the heater thermostat setting, thus causing GEWH energy use.
Although a solar heat transfer device could incorporate seasonally adjustable, user operated manual valves, or electronic actuated solenoids based on temperature sensing, the solenoids and controlling electronics are expensive, consume electricity to operate and are susceptible to power outages and various reliability issues or are not always automatic and, if not, require electricity for actuation. There is therefore a need for an automatic, low energy consumption system and method for use with a solar powered water heating system and a GEWH to minimize the energy consumed to heat the water supplied users.